Ultrasonic surgical instrument with cooling system

ABSTRACT

An ultrasonic surgical instrument including a blade that treats tissue and a fluid control system to cool the blade by pumping cooling fluid through the blade. The blade defines a blade lumen in fluid contact with an inflow and return conduit of the fluid control system. The fluid control system may further include a fluid reservoir holding the cooling fluid and a pump. The pump is configured to deliver the fluid from the fluid reservoir, through the inflow conduit and the blade lumen, and into return conduit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/696,208, filed on Nov. 26, 2019 which is a continuation of U.S.patent application Ser. No. 15/705,653, filed on Sep. 15, 2017, now U.S.Pat. No. 10,485,996, which is a continuation of U.S. patent applicationSer. No. 14/630,138, filed Feb. 24, 2015, now U.S. Pat. No. 9,764,166,which is a continuation-in-part of U.S. patent application Ser. No.14/284,741, filed May 22, 2014, now U.S. Pat. No. 9,622,767, whichclaims the benefit of and priority to U.S. Provisional PatentApplication Nos. 61/876,449 and 61/876,457, both of which filed Sep. 11,2013. The entire contents of each of the above applications areincorporated herein by reference.

BACKGROUND 1. Technical Field

The present disclosure relates generally to surgical instruments, and inparticular, to ultrasonic surgical instruments having fluid-cooledcomponents and related methods of cooling ultrasonic surgicalinstruments.

2. Discussion of Related Art

Energy-based tissue treatment is well known in the art. Various types ofenergy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal,laser, etc.) are applied to tissue to achieve a desired result.Ultrasonic energy, for example, may be delivered to tissue using asurgical probe that includes a transducer coupled with an end effectorconfigured to deliver the ultrasonic energy to tissue.

A typical ultrasonic surgical instrument incorporates a sinusoidaldriving signal which causes the mechanical tip of a waveguide to vibrateat a selected frequency, usually in the range of 20 KHz to 60 KHz, forcutting and/or coagulating tissue. Improved cutting may result fromincreased tissue-to-mechanical tip coupling caused by the high frequencyof vibration of the mechanical tip in relation to tissue. Improvedcoagulation may result from heat generated by coupling between the highfrequency vibrations of the mechanical tip and body tissue.

Ultrasonic surgical instruments may include any of a variety ofwaveguides configured to achieve a surgical result. For example, anultrasonic waveguide may be disposed at a distal end of the ultrasonicinstrument. The waveguide may include an end effector that includes acutting blade, shears, a hook, a ball, etc., and may be combined withother features such as jaws for grasping or manipulating tissue. Duringuse, waveguides on ultrasonic surgical instruments can reachtemperatures greater than 200° C.

SUMMARY

According to an aspect of the present disclosure, an ultrasonic surgicalinstrument is provided including a handle assembly, an elongated bodymember, a tool assembly, and a blade cooling system. The elongated bodymember extends distally from the handle assembly and defines alongitudinal axis. The elongated body member includes a waveguidepositioned coaxially within a lumen of an outer tube. The tool assemblyis coupled to a distal end of the elongated body member and includes ablade coupled to the distal end of the wave guide. The blade isconfigured to oscillate with respect to the outer tube forultrasonically treating tissue. The blade cooling system includes ablade conduit extending at least partially through the blade. A coolingfluid is configured to flow through the blade conduit. In embodiments,the blade cooling system is a closed-loop system. In some embodiments,the blade cooling system is an open system.

The elongated body member can also include a cooling conduit in fluidcommunication with the blade conduit. In aspects, the cooling conduit isdefined between the outer tube and the waveguide. In particular aspects,the cooling conduit is constructed of a microtube. In certain aspects,the cooling conduit and the blade conduit form a fully enclosed heatpipe such that the cooling fluid is configured to absorb heat from theblade and the cooling conduit is configured to release the absorbed heatto the surrounding environment.

In aspects, the blade conduit includes a blade outlet in a distalsurface of the blade. The blade cooling system may also include aninflow conduit in fluid communication with the blade conduit. In someaspects, the inflow conduit is constructed of a microtube. In particularaspects, the blade cooling system further includes a return conduit influid communication with the blade conduit. The return conduit can alsobe constructed of a polyimide microtube. In certain embodiments, theblade conduit includes a blade inlet between the inflow conduit and theblade conduit and positioned in a proximal portion of the blade. Theblade conduit can extend distally within the blade in parallelorientation relative to the longitudinal axis to a first end of a distalsection of the blade conduit which is orthogonal to the longitudinalaxis and spaced apart from a distal surface of the blade. A secondsegment of the blade conduit extends proximally within the blade inparallel orientation to the longitudinal axis from a second end of thedistal segment to a blade outlet. The blade conduit forms a continuousflow path through the blade from the blade inlet through the distalsection and exiting through the blade outlet. The blade outlet can bedistal to the blade inlet. The distal section of the blade conduit isspaced-apart from the distal surface of the blade a distance in therange of 0.005 to 0.025 mm.

According to another aspect of the present disclosure a surgical systemincludes an ultrasonic surgical instrument and a blade cooling system.The ultrasonic surgical instrument includes a handle assembly, anelongated body member, and a tool assembly. The elongated body memberincludes a waveguide having a blade coupled to the distal end. The bladeconfigured to oscillate with respect to the outer tube to ultrasonicallytreat tissue. The blade cooling system includes a blade conduit, aninflow conduit, and a fluid control system. The blade conduit isdisposed within and along the length of the blade. The inflow conduit isdisposed within and along the length of the elongated body member. Thefluid control system includes a pump configured to pump cooling fluidthrough the inflow conduit and the blade conduit.

The blade cooling system can also include a fluid reservoir storing acooling fluid therein such that the pump is configured to draw thecooling fluid from the fluid reservoir. In aspects, the blade coolingsystem further includes a return conduit and the blade conduit includesa distal section orthogonal to the longitudinal axis of the blade. Thedistal section spaced-apart from a distal surface of the blade. Thefluid control system configured to pump the cooling fluid through theinflow conduit, through the blade conduit including the distal section,and through the return conduit. The return conduit in fluidcommunication with the inflow conduit such that the blade cooling systemis a closed-loop system.

In aspects, the fluid control system controls activation anddeactivation of the pump in accordance with at least one property orcondition of the ultrasonic instrument. More specifically, a firstsensor may be provided to sense a temperature of the blade. The fluidcontrol system may thus be configured to activate the pump when thetemperature of the blade exceeds an upper temperature limit and/ordeactivate the pump when the temperature of the blade is less than alower temperature limit. A second sensor configured to sense a positionof an activation button of the ultrasonic surgical instrument mayadditionally or alternatively be provided. The fluid control system maythus be configured to activate and deactivate the pump for predeterminedperiods of time according to the position of the activation button(independently of or in conjunction with temperature-based feedbackcontrol).

According to another aspect of the present disclosure, a method fortreating tissue is provided including ultrasonically treating tissue byoscillating a blade of an ultrasonic surgical instrument in contact withtissue and activating a fluid control system to pump the cooling fluidthrough a blade conduit to cool the blade. The ultrasonic surgicalinstrument and/or fluid control system may be any of those describedherein.

In aspects, activating the fluid control system includes depressing anactivation button to activate the fluid control system. In aspects,depressing the activation button activates the fluid control system andoscillates the blade. The method may further include releasing theactivation button to deactivate the fluid control system and to ceaseoscillation of the blade. In some aspects, after the activation buttonis released the method includes delaying the deactivation of the fluidcontrol system until a predetermined amount of time has passed. Inparticular aspects, the method includes receiving a sensed temperatureof the blade after releasing the activation button and deactivating thefluid control system after the sensed temperature of the blade is belowa lower temperature limit.

In aspects, the method includes receiving a sensed temperature of theblade and verifying the sensed temperature of the blade is above anupper temperature limit before activating the fluid control system. Inaspects, the method includes deactivating the fluid control system afterthe sensed temperature of the blade is below a lower temperature limit.In some aspects, the method includes inputting the upper temperaturelimit and/or the lower temperature limit before ultrasonically treatingtissue. In particular aspects, the method includes varying the amount offluid flowing through the blade cooling system in response to the sensedtemperature of the blade.

Another ultrasonic surgical instrument provided in accordance withaspects of the present disclosure includes a handle assembly, anelongated body extending distally from the handle assembly, a waveguideextending at least partially through the elongated body, and a toolassembly including a blade coupled to a distal end of the waveguide. Theblade defines a blade lumen extending through the blade. The blade lumenhas closed proximal and distal ends. The blade further defines an outputin communication with the blade lumen towards the proximal end of theblade lumen. An inflow conduit enters the blade lumen via the output andextends distally through the blade lumen. The inflow conduit defines anopen distal end positioned within the blade lumen adjacent the distalend of the blade lumen. A return conduit defines an open distal endpositioned within the blade lumen adjacent the proximal end of the bladelumen. The return conduit exits the blade lumen via the output andextends proximally therefrom.

In aspects, the inflow and return conduits are microtubes. In aspects,the output is sealed about the inflow and return conduits. In aspects,the output is defined at an anti-node of the waveguide or at any othersuitable position along the waveguide. In aspects, an interior surfaceof the blade lumen and an outer surface of the inflow conduit define anannular gap therebetween. In aspects, the inflow and return conduitsextend along the exterior of the elongated body.

According to another aspect of the present disclosure a surgical systemincludes an ultrasonic surgical instrument and a blade cooling system.The ultrasonic surgical instrument may be similar to any of theultrasonic instruments detailed above. The blade cooling system includesa fluid reservoir and an inflow pump operatively coupled between thefluid reservoir and a proximal end of the inflow conduit.

In aspects, the inflow pump is configured to deliver a fluid from thefluid reservoir, through the inflow conduit and the blade lumen, andinto return conduit. In aspects, the return conduit is configured toreturn the fluid to the fluid reservoir or a return reservoir. Inaspects, the blade cooling system further includes a return pump coupledto a proximal end of the return conduit and configured to facilitate thereturn of the fluid from the return conduit into the fluid reservoir orreturn reservoir.

In aspects, the blade cooling system further includes a fluid controlsystem configured to control activation and deactivation of the inflowpump in accordance with at least one property or condition of theultrasonic surgical instrument. In aspects, a first sensor is configuredto sense a temperature of the blade, the fluid control system configuredto activate the inflow pump when the temperature of the blade exceeds anupper temperature limit, the fluid control system configured todeactivate the inflow pump when the temperature of the blade is lessthan a lower temperature limit. In aspects, a second sensor isconfigured to sense a position of an activation button of the ultrasonicinstrument, the fluid control system configured to activate anddeactivate the inflow pump for predetermined periods of time accordingto the position of the activation button.

According to another aspect of the present disclosure an ultrasonicsurgical instrument is provided including a handle assembly, anelongated body extending distally from the handle assembly, a waveguideextending at least partially through the elongated body, and a toolassembly including a blade coupled to a distal end of the waveguide. Theblade defines a blade lumen extending through the blade. The blade lumenhas closed proximal and distal ends. The blade further defines an outputin communication with the blade lumen towards the proximal end of theblade lumen. An inflow conduit and a return conduit are also provided.The inflow and return conduits extend from a proximal end of theelongated body, distally along an outer surface of the elongated body,through the output, and into the blade lumen.

In aspects, the inflow conduit is configured to couple to a first pumpat a proximal end thereof, the first pump configured to deliver a fluidthrough the inflow conduit the blade lumen. In aspects, the returnconduit is configured to couple to a second pump at a proximal endthereof, the second pump configured to push and/or pull fluid from theblade lumen through the return conduit. In aspects, the inflow conduitextends distally through the blade lumen and defines an open distal endpositioned within the blade lumen adjacent the distal end of the bladelumen.

In aspects, the return conduit defines an open distal end positionedwithin the blade lumen adjacent the proximal end of the blade lumen. Inaspects, the output is sealed about the inflow and return conduits. Inaspects, the inflow and return conduits are microtubes.

Further, to the extent consistent, any of the aspects described hereinmay be used in conjunction with any or all of the other aspectsdescribed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure are described hereinbelow withreference to the drawings, wherein:

FIG. 1 is a perspective view of a surgical system provided in accordancewith the present disclosure including a surgical instrumentincorporating a cooling system;

FIG. 2 is an exploded view of the components of the elongated bodyportion of the surgical instrument of FIG. 1 ;

FIG. 3 is an enlarged view of the tool assembly of the surgicalinstrument of FIG. 1 with a portion of the outer tube of the surgicalinstrument cut away;

FIG. 3A is an enlargement of the distal end of the surgical instrumentof FIG. 1 with the tool assembly in the closed position;

FIG. 4 is a longitudinal, cross-sectional view of the distal end of thesurgical instrument of FIG. 1 illustrating operation of the coolingsystem;

FIG. 5 is an enlarged view of the detail area “5” of FIG. 4 ;

FIG. 6 is a perspective view of another surgical system provided inaccordance with the present disclosure including a surgical instrumentincorporating a cooling system;

FIG. 7 is a longitudinal, cross-sectional view of the distal end of thesurgical instrument of FIG. 6 illustrating operation of the coolingsystem;

FIG. 8 is a longitudinal, cross-sectional view of another cooling systemprovided in accordance with the present disclosure and configured foruse with the surgical instrument of FIG. 6 ;

FIG. 8A is an enlarged view of the detail area “8A” of FIG. 8 ;

FIG. 9 is a perspective view of yet another surgical system provided inaccordance with the present disclosure including a surgical instrumentincorporating a cooling system;

FIG. 9A is an enlarged view of the detail area “9A” of FIG. 9 ;

FIG. 10 is a longitudinal, cross-sectional view of the blade of thesurgical instrument of FIG. 9 illustrating the cooling system;

FIG. 11 is a longitudinal, cross-sectional view of another blade coolingsystem provided in accordance with the present disclosure including acooling conduit disposed within a waveguide;

FIG. 12 is a perspective view of yet another surgical system provided inaccordance with the present disclosure including a surgical instrumentincorporating a cooling system;

FIG. 12A is an enlarged view of the detail area “12A” of FIG. 12 ;

FIG. 13 is an enlarged, perspective view of the distal end of thesurgical instrument of FIG. 12 ;

FIG. 14 is a longitudinal, cross-sectional view of the blade of thesurgical instrument of FIG. 12 ; and

FIG. 15 is a perspective view of another surgical system provided inaccordance with the present disclosure including a surgical instrumentincorporating a cooling system.

DETAILED DESCRIPTION

Embodiments of the present disclosure are now described in detail withreference to the drawings in which like reference numerals designateidentical or corresponding elements in each of the several views. Asused herein, the term “clinician” refers to a doctor, a nurse, or anyother care provider and may include support personnel. Throughout thisdescription, the term “proximal” will refer to the portion of the deviceor component thereof that is closest to the clinician and the term“distal” will refer to the portion of the device or component thereofthat is furthest from the clinician. Throughout the drawings, the arrowswithin and adjacent to portions of the cooling system indicate thedirection of the flow of the cooling fluid.

Referring now to FIG. 1 , one exemplary embodiment of an ultrasonicsurgical instrument configured for use in accordance with the presentdisclosure is shown generally identified by reference numeral 10,although it is also envisioned that the aspects and features of thepresent disclosure be similarly incorporated into any suitableultrasonic surgical instrument. Ultrasonic surgical instrument 10generally includes a handle assembly 12, an elongated body portion 14,and a tool assembly 16. Handle assembly 12 supports a battery assembly18 and an ultrasonic transducer and generator assembly (hereinafter“TAG”) 20. Handle assembly 12 includes a rotatable nozzle 22, anactivation button 24, and a clamp trigger 26. Battery assembly 18 andTAG 20 are each releasably secured to a central body 28 of handleassembly 12 and are removable from central body 28 to facilitatedisposal of the entire device, with the exception of battery assembly 18and TAG 20.

With additional reference to FIG. 2 , elongated body portion 14 includesa waveguide 30 which extends from handle assembly 12 to tool assembly 16(FIG. 1 ). A distal end of waveguide 30 defines a blade 32, which willbe discussed in further detail below. A proximal end of waveguide 30 hasa threaded extension 34 for engaging TAG 20. Waveguide 30 furtherincludes a proximal tapered portion 30 a and distal tapered portions 30b and 30 c. A series of annular abutments 31 a-d are disposed along,e.g., machined onto, waveguide 30 at node points along waveguide 30.

An inner tube 36 is positioned about waveguide 30 between proximaltapered portion 30 a and distal tapered portion 30 b of waveguide 30. Adistal seal member 38 is supported about waveguide 30 distally of adistal end of inner tube 36 and proximally of distal tapered portion 30c of waveguide 30 to provide a fluid-tight seal at the distal end ofelongated body portion 14 between waveguide 30 and an inner surface of amiddle tube 42. Ultrasonic energy is isolated from transfer to middletube 42 by inner tube 36. A series of splines 44 are formed at theproximal end of waveguide 30. Splines 44 engage splines (not shown)formed on an inner surface of a torque adapter 46 to rotatably securetorque adapter 46 to waveguide 30. Torque adapter 46 also includesdiametrically opposed wings 48 which are positioned in recesses (notshown) in rotatable nozzle 22 to secure torque adapter 46 to rotatablenozzle 22.

With additional reference to FIGS. 3 and 3A, middle tube 42 ispositioned about inner tube 36 and includes a distal end having a corsetfeature 50 and a pair of spaced clamp support arms 52. Corset feature 50is positioned to receive distal seal member 38 to maintain distal sealmember 38 in the proper position about the distal end of waveguide 30.Distal seal member 38 is positioned at a node point along waveguide 30.An O-ring 40 is supported about corset feature 50 to provide afluid-tight seal between an outer surface of middle tube 42 and an innersurface of an outer tube 66.

With particular reference to FIGS. 3 and 3A, spaced clamp support arms52 each define an opening 54 for pivotally receiving pivot members 56formed on a clamp member 58 of tool assembly 16. Clamp member 58 of toolassembly 16 is pivotal between an open position (FIG. 3 ), wherein clampmember 58 is spaced from blade member 32, and a closed position (FIG.3A), wherein clamp member 58 is in juxtaposed alignment with blademember 32. Clamp member 58 is moved between the open position and theclosed position in response to actuation of clamp trigger 26 (FIG. 1 ).

Outer tube 66 is slidably repositionable between an advanced positionand a retracted position. Upon movement of outer tube 66 from theadvanced position to the retracted position, clamp member 58 is movedfrom the open position (FIG. 3 ) to the closed position (FIG. 3A). Aproximal end of outer tube 66 includes an elongated slot 70 (FIG. 2 )which receives projections (not shown) of rotatable nozzle 22 (FIG. 1 )such that outer tube 66 is rotatably secured to, but slidable about, theprojections to facilitate movement of outer tube 66 between the advancedand retracted positions.

Referring again to FIG. 2 , the proximal end of outer tube 66 includes abifurcated portion that defines an axially extending throughbore 72 thatslidably receives wings 48 of torque adapter 46. A pair of diametricallyopposed windows 74 are formed in the proximal end of outer tube 66.Windows 74 receive bosses (not shown) formed in handle assembly 12 (FIG.1 ) to couple outer tube 66 to handle assembly 12 (FIG. 1 ).

Referring to FIG. 4 , one embodiment of a blade cooling system 80incorporated into ultrasonic surgical instrument 10 (FIG. 1 ) inaccordance with the present disclosure is shown including an inflowconduit 82 and a blade lumen 84. Inflow conduit 82 is annularly definedbetween middle tube 42 and waveguide 30. Blade lumen 84 is formed withinand extends substantially through the length of blade 32. Blade lumen 84includes one or more blade inlets 84 a, e.g., one or more blade inlets84 a extending radially outwardly from blade lumen 84, and a bladeoutlet 84 b. Blade inlet(s) 84 a may be positioned at an anti-node pointalong waveguide 30 or at any other suitable position therealong. Bladeoutlet 84 b is defined at the distal end of blade 32. Blade lumen 84 isin fluid communication with inflow conduit 82 via blade inlet(s) 84 a.Blade outlet 84 b includes an angled surface 85 b disposed at an angle θto the inner surface of blade lumen 84 as shown in FIG. 5 to facilitatethe outflow of fluid from blade lumen 84. Angle θ may be in a range ofabout 0° to about 45°. Blade lumen 84 may have a diameter in the rangeof about 0.25 mm to about 0.65 mm. In embodiments, blade inlet 84 a mayhave a diameter in the range of about 0.25 mm to about 1.00 mm. Othersuitable configurations are also contemplated.

As noted above, inflow conduit 82 is defined between middle tube 42 andwaveguide 30. Alternatively or additionally, inflow conduit 82 may bedefined between outer tube 66 and middle tube 42. In such embodiments,inflow conduit 82 includes an input opening (not shown) in inner tube 36and/or middle tube 42, which provides fluid communication between inflowconduit 82 and blade inlet 84 a.

Annular abutment 31 d is positioned within inflow conduit 82 andconfigured to permit a cooling fluid 89 (FIG. 1 ) to flow through inflowconduit 82 to blade inlet 84 a. In embodiments, as opposed to defininginflow conduit 82 annularly between middle tube 42 and waveguide 30,inflow conduit 82 may comprise one or more polyimide microtubes (orother suitable microtubes) disposed between inner tube 36 and waveguide30 and extending proximally from the proximal end of elongated bodymember 14. In such configurations, annular abutment 31 d may include apassage (or passages) dimensioned and configured to slidably receive theone or more microtubes.

Referring to FIGS. 1-4 , blade cooling system 80 further includes afluid reservoir 88 in fluid communication with inflow conduit 82. Fluidreservoir 88 may be positioned external to instrument 10, positioned onhandle assembly 12, or positioned within handle assembly 12. Inembodiments where fluid reservoir 88 is external to instrument 10,central body 28 of handle assembly 12 includes an inflow port 81 toprovide fluid communication between fluid reservoir 88 and inflowconduit 82. Fluid reservoir 88 is configured to hold a supply of coolingfluid 89. Cooling fluid 89 can be any fluid capable of conductivelyand/or conventionally absorbing heat from a thermally conductive solidsurface. Exemplary cooling fluids include but are not limited to water,saline, compressed air, compressed nitrogen, compressed oxygen, etc.

Blade cooling system 80 further includes a fluid control system 90having a pump 92. Pump 92 is configured to pump cooling fluid 89 fromfluid reservoir 88 through inflow conduit 82 and blade lumen 84 suchthat cooling fluid 89 exits blade 32 through blade outlet 84 b. Inembodiments, fluid control system 90 is selectively operated by aclinician. In some embodiments, fluid control system 90 is automaticallyoperated by conditions of instrument 10 sensed by fluid control system90. Fluid control system 90 may include a plurality of sensors 94 a-dpositioned on and/or within instrument 10 to provide feedback ofconditions of instrument 10. Sensors 94 a-d may include, for example, ablade thermocouple 94 a configured to measure the temperature of blade32, a clamp sensor 94 b (FIG. 3 ) configured to determine the positionof clamp 58 and/or the position of clamp trigger 26, a waveguidethermocouple 94 c configured to measure the temperature of a portion ofwaveguide 14, and an activation sensor 94 d configured to measure theposition of activation button 24. Other suitable sensors and/orcombinations of sensors are also contemplated, as are any other suitablemechanisms for providing feedback and/or indicating a state, parameter,condition, etc. of a component of instrument 10 and/or the surroundingenvironment.

When pump 92 of fluid control system 90 is activated, pump 92 drawscooling fluid 89 from fluid reservoir 88 and pumps cooling fluid 89through inflow conduit 82 and blade lumen 84. When cooling fluid 89 ispumped through blade lumen 84, cooling fluid 89 flows out of bladeoutlet 84 b formed through the distal surface of blade 32 (see FIGS.3-3A). As cooling fluid 89 exits from blade outlet 84 b, cooling fluid89 can form a mist. As angle θ of angled surface 85 b is decreased, themisting of cooling fluid 89 decreases. As cooling fluid 89 fluid flowsthrough blade lumen 84, cooling fluid 89 absorbs heat from blade 32 suchthat blade 32 is cooled by blade cooling system 80. Cooling fluid 89flowing through inflow conduit 82 also absorbs heat from waveguide 30.Fluid control system 90 regulates the amount of cooling fluid 89 thatpump 92 draws from fluid reservoir 88 and pumps through blade coolingsystem 80 thus controlling the cooling of blade 32.

Fluid control system 90 may be configured to control the cooling ofblade 32 via regulating pump 92 such as, for example, by: activatingpump 92 to continually pump cooling fluid 89 through blade coolingsystem 80; activating/deactivating pump 92 to pump cooling fluid 89through blade cooling system 80 when activation button 24 (FIG. 1 ) isdepressed (actuated); activating/deactivating pump 92 to pump coolingfluid 89 through blade cooling system 80 when activation button 24 (FIG.1 ) is released (un-actuated); activating/deactivating pump 92 to pumpcooling fluid 89 through blade cooling system 80 according to apredetermined schedule; activating/deactivating pump 92 to pump coolingfluid 89 through blade cooling system 80 once activation button 24 (FIG.1 ) has been depressed (actuated) for a predetermined period of time;activating/deactivating pump 92 to pump cooling fluid 89 through bladecooling system 80 once activation button 24 (FIG. 1 ) has been released(un-actuated) for a predetermined amount of time; and/oractivating/deactivating pump 92 to pump cooling fluid 89 through bladecooling system 80 based upon temperature feedback so as to maintain thetemperature of blade 32 and/or waveguide 30 below a predeterminedthreshold temperature or within a predetermined temperature range. Asdescribed in detail below, fluid control system 90 may include sensors94 a-d, or any other suitable mechanisms for providing feedback and/orindicating a state, parameter, condition, etc. of a component ofinstrument 10 and/or the surrounding environment, to facilitatecontrolling of pump 92. Other control systems, mechanisms, methods,and/or protocols are also contemplated.

As mentioned above, in some embodiments, fluid control system 90,together with blade cooling system 80, may be configured to maintainblade 32 below a predetermined temperature. In such a configuration, theclinician inputs an upper temperature limit into fluid control system90. In embodiments, the upper temperature limit may also be preset atthe time of manufacture of fluid control system 90. Fluid control system90 activates pump 92 when blade thermocouple 94 a determines thetemperature of blade 32 is approaching the upper temperature limit. Whenpump 92 is activated, pump 92 pumps cooling fluid 89 through bladecooling system 80 to prevent blade 32 from exceeding the uppertemperature limit. The amount of fluid pumped through blade coolingsystem 80 may also be varied depending on the sensed temperature.

Additionally, blade 32 may be maintained within a range of predeterminedtemperatures. In such a configuration, the clinician inputs an upper andlower temperature limit of the range of predetermined temperatures intofluid control system 90. Similar to the previous configuration, theupper and lower temperature limits can be preset. Fluid control system90 activates pump 92 (or increases the rate at which fluid is pumped)when blade thermocouple 94 a determines the temperature of blade 32 isapproaching the upper temperature limit to cool or decrease thetemperature of blade 32. When fluid control system 90 determines thetemperature of blade 32 is approaching the lower temperature limit, asmeasured by blade thermocouple 94 c, fluid control system 90 deactivatespump 92 (or decreases the rate at which fluid is pumped) stopping (orreducing) the flow of cooling fluid 89 through blade 32.

Additionally or alternatively, blade cooling system 80 may be configuredto cool blade 32 after a clinician has activated and deactivated blade32. In this configuration blade 32 is allowed to heat up when used todissect and/or coagulate tissue, but is actively cooled via bladecooling system 10 once blade 32 is no longer in use. In such aconfiguration, fluid control system 90 activates pump 92 when bladethermocouple 94 a determines the temperature of blade 32 exceeds anupper temperature limit and activation sensor 94 d (or other suitablemechanism) determines that activation button 24 is in the released(un-actuated) position. Fluid control system 90 may deactivate pump 92when the temperature of blade 32 reaches a lower temperature limit, orwhen activation button 24 is in the depressed (actuated) position. Fluidcontrol system 90 may further include a clamp sensor 94 b (or othersuitable mechanism) to determine the position of clamp 58, i.e. open orclosed. When clamp 58 is in the open position, as determined by clampsensor 94 b, and the temperature of blade 32 exceeds the uppertemperature limit, fluid control system 90 activates pump 92. On theother hand, when clamp 58 or the temperature of blade 32 is below thelower temperature limit, fluid control system 90 deactivates pump 92.

Referring to FIGS. 6 and 7 , another ultrasonic surgical instrument 110is provided in accordance with the present disclosure including awaveguide 130 and incorporating a blade cooling system 180. Ultrasonicsurgical instrument 110 and blade cooling system 180 are substantiallysimilar to ultrasonic surgical instrument 10 and blade cooling system 80(FIGS. 1-5 ), with similar elements represented by similar numerals. Assuch only the differences are discussed in detail below.

Blade cooling system 180 is a closed circuit and includes an inflowconduit 182, a blade lumen 184, and a return conduit 186. Inflow conduit182 is defined between middle tube 142 and waveguide 130. Inflow conduit182 is in fluid communication with blade lumen 184 via one or more bladeinlets 184 a disposed at an anti-node point along waveguide 130. A sealis disposed about or in proximity to annular abutment 131 d to seal adistal end of inflow conduit 182. In embodiments, annular abutment 131 dforms a seal at the distal end of inflow conduit 182. Blade lumen 184 isdefined within and extends through blade 132. Blade lumen 184 includesblade inlet(s) 184 a and a blade outlet 184 b. Blade inlet(s) 184 a isproximal of the seal of, about, or in proximity to annular abutment 131d to permit the inflow of fluid from inflow conduit 182 into bladeinlet(s) 184 a. Blade lumen 184 extends distally from blade inlet 184 asuch that blade lumen 184 extends substantially along the length ofblade 132 in a parallel orientation to the longitudinal axis. A distalsection 184 c of blade lumen 184 is orthogonal to the longitudinal axisof blade 132 (or otherwise curved, bent, or angled) such that distalsection 184 c of blade lumen 184 is parallel (or otherwise curved, bent,or angled) to a distal surface 132 a of blade 132. Distal section 184 cis spaced-apart from distal surface 132 a of blade 132 and distalsection 184 c defining a gap 187 therebetween. Gap 187 may be in therange of about 0.005 to about 0.025 mm; however, larger and smallerdimensions for gap 187 are also contemplated. Blade lumen 184 returnsalong a length of blade 132 from distal section 184 c to blade outlet184 b. Blade outlet 184 b may be disposed at an anti-node point alongwaveguide 130 or any other suitable position therealong and is disposedin fluid connection with return conduit 186, e.g., via positioning ofblade outlet 184 b proximally of distal seal member 138 and distally ofthe seal of, about, or in proximity of annular abutment 131 d. Returnconduit 186 is defined between middle tube 142 and outer tube 166 and isin fluid communication with blade outlet 184 b through a slot 142 a ofmiddle tube 142. An O-Ring 140 is positioned distal to slot 142 abetween middle tube 142 and outer tube 166 to seal the distal end ofreturn conduit 186.

Similar to inflow conduit 82 described above (FIG. 4 ), inflow conduit182 and return conduit 186 may alternatively be formed from polyimidemicrotubes. For example, inflow conduit 182 can be a polyimide microtubedisposed between middle tube 142 and waveguide 130 and in fluidcommunication with blade inlet 184 a and return conduit 186 can be apolyimide microtube in fluid communication with blade outlet 184 bpassing through slot 142 a of middle tube 142 and extending proximallythrough a channel disposed between outer tube 166 and middle tube 142.Moreover, as shown in FIGS. 8 and 8A, in embodiments where microtubesare provided, conduits 182, 186 of polyimide microtubes may be disposedwithin the same channel, e.g., between the middle tube 142 and thewaveguide 130, and blade outlet 184 b can be proximal to annularabutment 31 d.

In embodiments, return conduit 186 is in fluid communication with inflowconduit 182 such that the fluid continually circulates through bladecooling system 180. In some embodiments, blade cooling system 180includes a fluid control system 190 having a pump 192 positioned betweenreturn conduit 186 and inflow conduit 182 to circulate cooling fluid 189through blade cooling system 180. Pump 192 can be disposed withincentral body 128 of handle assembly 112. In certain embodiments, bladecooling system 180 further includes a fluid reservoir 188 positionedbetween and in fluid communication with return conduit 186 and inflowconduit 182. Fluid reservoir 188 can be disposed within central body 128or external to instrument 110. When fluid reservoir 188 is disposedexternal to instrument 110, central body 128 includes an inflow port 182a and a return port 186 a in fluid communication with inflow conduit 182and return conduit 186, respectively. Fluid control system 190 may alsoinclude a sensors 194 a-d similar to the sensors 94 a-d discussed abovewith respect to instrument 10 (FIGS. 1-5 ) and may also include a returnconduit thermocouple 194 e (FIG. 7 ) configured to measure thetemperature of cooling fluid 189 in return conduit 186.

Blade cooling system 180 of instrument 110 functions substantiallysimilar to blade cooling system 80 of instrument 10. However, as bladecooling system 180 is a closed system, cooling fluid 189 flows throughinflow conduit 182 through blade lumen 184 and returns through returnconduit 186 before recirculating through blade cooling system 180. Ascooling fluid 189 flows through blade cooling system 180, cooling fluid189 absorbs heat from waveguide 130 and/or blade 132. The absorbed heatmay be released to the surrounding environment through an outer surfaceof outer tube 166, central portion 128 of housing assembly 112, and/orfrom fluid reservoir 188. Additionally, fluid reservoir 188 may beactively cooled to facilitate cooling of the fluid 189 returned fromblade 132 prior to recirculation.

Referring to FIGS. 9-10 , another ultrasonic surgical instrument 210 isprovided in accordance with the present disclosure including a waveguide230 and incorporating a blade cooling system 280. Ultrasonic surgicalinstrument 210 and blade cooling system 280 are substantially similar toultrasonic surgical instrument 10 and blade cooling system 80 (FIGS. 1-5), with similar elements represented by similar numerals. As such onlythe differences are discussed in detail below.

Blade cooling system 280 includes a blade lumen 284 and a coolingconduit 286. It is envisioned that the distal end 284 a of blade lumen284 is spaced from a distal surface 232 a of blade 232 by a gap 287. Gap287 may be in the range of about 0.005 to about 0.025 mm; however,larger and smaller dimensions for gap 287 are also contemplated. Bladelumen 284 extends proximally within and substantially along the lengthof blade 232 to a blade outlet 284 b. Cooling conduit 286 is disposedwithin blade lumen 284 and a longitudinal slot 266 a in the outersurface of outer tube 266 along a length of an elongated body portion214 (see FIG. 9A). A proximal end 286 b of cooling conduit 286 may besealed or may be configured to couple to a fluid reservoir similarly asdescribed above with respect to previous embodiments. A distal end 286 aof cooling conduit 286 is proximate to distal end 284 a of blade lumen284. Cooling conduit 286 can be a polyimide tube.

Referring to FIG. 11 , a blade cooling system 380 is provided inaccordance with the present disclosure incorporated within a waveguide330 and blade 332. Waveguide 330 and blade cooling system 380 aresubstantially similar to waveguide 30 and blade cooling system 80 (FIGS.1-5 ), with similar elements represented by similar numerals, and may beused with any of ultrasonic instruments 10, 110, and 210. It is alsocontemplated that blade cooling system 380 can be used with othersuitable ultrasonic instruments. As such only the differences arediscussed in detail below.

Blade cooling system 380 is a closed heat pipe system and includes ablade lumen 384 and a cooling conduit 386. It is envisioned that thedistal end 384 a of blade lumen 384 is spaced from a distal surface 332a of blade 332 by a gap 387. Gap 387 may be in the range of about 0.005to about 0.025 mm; however, larger and smaller dimensions for gap 387are also contemplated. Blade lumen 384 extends proximally within andsubstantially along the length of blade 332 to a blade outlet 384 b.Blade outlet 384 b is in fluid communication with cooling conduit 386,i.e., blade lumen 384 and cooling conduit 386 cooperate to define a heatpipe extending through and between at least a portion of both waveguide330 and blade 332. Cooling conduit 386 is disposed within waveguide 330.Cooling conduit 386 includes a conduit opening 386 a at a distal end ofwaveguide 330 in fluid communication with blade outlet 384 b and aproximal or closed end 386 b is proximate to the proximal end ofwaveguide 330. Closed end 386 b of cooling conduit 386 is sealed. Inembodiments, the inner wall of the blade lumen 384 and/or coolingconduit 386 includes a wick structure (not shown) configured to exertcapillary pressure on the cooling fluid when the cooling fluid is in aliquid phase. The wick structure may be a series of grooves parallel tothe longitudinal axis of waveguide 330. Cooling conduit 386 isconstructed of a material with a high thermal efficiency, e.g., copper,polyimide micro tubing, etc.

In use, as the temperature of blade 332 increases, cooling fluid 389which is disposed within blade lumen 384 absorbs heat from blade 332transitioning cooling fluid 389 from a liquid phase to a vapor phase.Cooling fluid 389 in the vapor phase travels through blade coolingsystem 380 from blade lumen 384 to cooling conduit 386 where the coolingfluid 389 releases the absorbed heat through the surface of coolingconduit 386, i.e., waveguide 330, to the surrounding environment. Ascooling fluid 389 releases the absorbed heat, cooling fluid 389 returnsfrom the vapor phase to the liquid phase. When cooling fluid 389 returnsto the liquid phase, cooling fluid 389 returns to blade lumen 384 torepeat the cycle. As can be appreciated, the distal-to-proximal movementof the vapor and the proximal-to-distal movement of the liquid can befacilitated by gravity when in use as blade 332 is generally angleddownwardly relative to waveguide 330 into the surgical site.

The present disclosure also provides methods of manufacturing ultrasonicsurgical instruments including cooling systems, such as thoseinstruments detailed above. The method may include fabricating awaveguide, fabricating two halves of a blade separated along thelongitudinal axis of the blade, cutting a portion of a conduit in eachhalf of the blade, welding the two halves of the blade into a blade, andwelding the blade to the distal end of the waveguide. As such, theconduits extending through the blade, as detailed above, can be readilyformed to a desired configuration.

Cutting a portion of the conduit in each half of the blade mayparticularly include cutting a half-cylindrical channel along the lengthof the blade half including an opening in the outer surface of the bladeand at the distal end of the blade. Blade 32 (FIG. 4 ) may bemanufactured in this manner. Alternatively, to achieve blade 132 (FIG. 7), the cutting a portion of the conduit in each half of the bladeincludes cutting a half-cylindrical channel along the length of theblade half from a first opening in the outer surface of the blade, alongthe length of the blade towards the distal end, continuing the channelsubstantially parallel to the distal end of the blade defining a gapbetween the channel and the distal end of the blade, continuing thechannel back along the length of the blade towards the proximal end ofthe blade, continuing the channel out a second opening in the outersurface of the blade substantially opposing the first opening. Thecutting in either of the above embodiments may be accomplished by lasercutting or etching.

Welding the two halves of the blade into a blade may include aligningthe two halves of the blade such that the half-cylindrical channels ineach blade are positioned adjacent to each other to form a continuouscylindrical conduit within the blade. Welding the two halves may includelaser welding the two halves of the blade together. Welding the blade tothe waveguide may include laser welding the proximal end of the blade tothe distal end of the waveguide.

In embodiments, the distal end of the waveguide includes threadsconfigured to cooperate with threads of the blade to secure thewaveguide to the blade. In some embodiments, the blade lumen is formedby drilling through a portion of the blade such that the distal end ofthe blade remains closed and does not require welding. ElectricalDischarge Machining (EDM) may alternatively be used to make the bladelumen, followed by the distal end of the blade being welded shut. Othersuitable manufacturing methods are also contemplated.

Referring now to FIGS. 12-14 , another embodiment of an ultrasonicsurgical instrument configured for use in accordance with the presentdisclosure is shown generally identified by reference numeral 410.Ultrasonic surgical instrument 410 is similar to and may include any ofthe aspects and/or features of any of the instruments detailed above.Thus, for purposes of brevity, only the differences between ultrasonicsurgical instrument 410 and the above instruments will be detailedbelow, while similarities will be summarily described or omittedentirely.

Ultrasonic surgical instrument 410 generally includes a handle assembly412, an elongated body portion 414, a tool assembly 416 having a blade432, and a blade cooling system 480. Blade cooling system 480 has afluid reservoir 488 that may be separate from ultrasonic surgicalinstrument 410 (as shown), on handle assembly 412, or within handleassembly 412. Fluid reservoir 488 is configured to hold a supply ofcooling fluid 489, which can be any suitable fluid such as thosedetailed above.

Blade cooling system 480 further includes a fluid control system 490having a pump 492 configured to pump cooling fluid 489 from fluidreservoir 488 through blade 432 of ultrasonic surgical instrument 410via a cooling inflow conduit 482. Cooling fluid 489 absorbs heat fromblade 432 of ultrasonic surgical instrument 410 and is returned througha cooling return conduit 486. Heated cooling fluid 489 may be returnedto fluid reservoir 488, thus forming a closed-loop system, or may bereleased into a separate return reservoir (not shown) as part of anopen-loop system.

As shown in FIGS. 12 and 12A, cooling inflow and return conduits 482,486 are disposed on the outer surface of elongated body portion 414 ofultrasonic surgical instrument 410 and extend substantially along thelength thereof. Positioning conduits 482, 486 on the exterior ofelongated body portion 414 helps inhibit the heating of waveguide 430(FIG. 13 ) and other internal components extending through elongatedbody potion 414 via the heated fluid returning through the returnconduit 486. A proximal end 482 a of inflow conduit 482 is configured tocouple to pump 492 via handle assembly 412 (as shown) or separatelytherefrom and a proximal end 486 a of return conduit 486 is configuredto couple to fluid reservoir 488 (or a separate return fluid reservoir(not shown)) via handle assembly 412 (as shown) or separately therefrom.Distal and proximal apertures 466 a, 466 b, respectively, are definedwithin elongated body portion 414 to enable conduits 482, 486 to exitand enter elongated body portion 414, respectively. However, it is alsocontemplated that ultrasonic surgical instrument 410 be configured withconduits 482, 486 extending within elongated body portion 414.

Referring to FIGS. 13 and 14 , blade 432 defines a blade lumen 434 thatis formed within and extends substantially along the length of blade432. Blade lumen 434 may be coaxial with or extend in a parallelorientation relative to a longitudinal axis defined by blade 432. Bladelumen 434 defines a closed distal end. Inflow conduit 482 and returnconduit 486 enter blade lumen 434 through a blade output 460 definedtowards the proximal end of blade lumen 434. A seal is formed aboutblade output 460 and around inflow and outflow conduits 482, 486 toinhibit the escape of fluid thereform. The seal may be affixed to theblade output 460 and conduits 482, 486. Alternatively, the seal may bereleasably attached to blade output 460 permitting access to blade lumen434. Blade output 460 may be positioned at an anti-node point alongwaveguide 430 of ultrasonic surgical instrument 410 or at any othersuitable position therealong. Inflow conduit 482 is disposed within andextends distally through blade lumen 434. Return conduit 486 is disposedwithin the proximal end of blade lumen 434. Inflow conduit 482 has asmaller diameter than blade lumen 434 leaving an annular gap 436 (FIG.14 ) between the inner surface of blade 432 defining blade lumen 434 andthe outer surface of inflow conduit 482. Blade lumen 434 may have adiameter in the range of about 0.25 mm to about 0.65 mm; however, othersuitable configurations are also contemplated. During operation, coolingfluid 489 is pumped or otherwise circulated distally through inflowconduit 482, exits a distal end of inflow conduit 482 at the distal endof blade lumen 434, and travels proximally back through blade lumen 434within annular gap 436, ultimately being received by return conduit 486,e.g., under suction force or under urging from the pumped inflowingfluid. Inflow and return conduits 482, 486 may comprise one or morepolyimide microtubes (other suitable microtubes, or may be formed in anyother suitable fashion).

Referring again to FIGS. 12-14 , the fluid control system 490 is similarto the fluid control systems described above except for the relativepositions of inflow and return conduit 482, 486 and the flow path ofcooling fluid 489. When pump 492 of fluid control system 490 isactivated, pump 492 draws cooling fluid 489 from fluid reservoir 488 andpumps cooling fluid 489 through inflow conduit 482 into the distal endof blade lumen 434. As cooling fluid 489 fluid flows proximally backthrough blade lumen 434 within annular gap 436, cooling fluid 489absorbs heat from blade 432 such that blade 432 is cooled. The coolingfluid 489 is then pushed and/or pulled through the return conduit 486into fluid reservoir 488, creating a closed circuit, or pushed and/orpulled into a return reservoir (not shown) creating an open circuit.Fluid control system 490 regulates the amount of cooling fluid 489 thatpump 492 draws from fluid reservoir 488 and pumps through blade coolingsystem 480, thus controlling the cooling of blade 432. Control may beperformed similarly as detailed above with respect to the previousembodiments, or in any other suitable fashion.

Referring to FIG. 15 , another ultrasonic surgical instrument 510 isprovided in accordance with the present disclosure incorporating a bladecooling system 580. Ultrasonic surgical instrument 510 is similar toultrasonic surgical instrument 410 (FIGS. 12-14 ), except for theconfiguration of blade cooling system 580, as detailed below.

Blade cooling system 580 includes an inflow conduit 582, a returnconduit 586, an inflow pump 592, and a return pump 594. Inflow conduit582 and return conduit 586 may be formed from polyimide microtubes (orin any other suitable manner).

Similar to the cooling systems described above, return conduit 586 is influid communication with inflow conduit 582 such that the fluidcontinually circulates through blade cooling system 580. Blade coolingsystem 580 includes a fluid control system 590 having an inflow pump 592positioned between a fluid reservoir 588 and inflow conduit 582 and areturn pump 594 positioned between return conduit 586 and fluidreservoir 588. Alternatively, return pump 594 may be positioned betweenreturn conduit 584 and a separate return reservoir (not shown) to definean open-loop system. Inflow and return pumps 592, 594 can be externallydisposed (as shown), or may be disposed within central body 528 ofhandle assembly 512. Fluid control system 590 may also include sensors(not shown) similar to the sensors discussed above to enablefeedback-based control.

Similar to the fluid control systems detailed above, when inflow pump592 of fluid control system 590 is activated, inflow pump 592 drawscooling fluid 589 from fluid reservoir 588 and pumps cooling fluid 589through inflow conduit 582 and the blade of ultrasonic surgicalinstrument 510. As cooling fluid 589 fluid flows through blade lumen(not shown) of the blade, return pump 594 is activated to draw theheated cooling fluid 589 from the blade lumen (not shown), through thereturn conduit 586, and into the fluid reservoir 588 or alternativelythe return reservoir (not shown). The inflow and return pumps 592, 594may operate simultaneously. However, the operation times of pumps 592,594 may also be staggered. Fluid control system 590 may include sensors(not shown), or any other suitable mechanisms for providing feedbackand/or indicating a state, parameter, condition, etc. of a component ofsurgical instrument 510 and/or the surrounding environment, tofacilitate controlling of inflow and return pumps 592, 594. Fluidcontrol system 490 (FIG. 12 ) may similarly include such features. Othercontrol systems, mechanisms, methods, and/or protocols are alsocontemplated for either or both embodiments.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Any combination ofthe above embodiments is also envisioned and is within the scope of theclaimed invention. Therefore, the above description should not beconstrued as limiting, but merely as exemplifications of particularembodiments. Those skilled in the art will envision other modificationswithin the scope and spirit of the claims appended hereto.

What is claimed is:
 1. An ultrasonic surgical instrument, comprising: ahandle assembly; an elongated body extending distally from the handleassembly; a waveguide extending at least partially through the elongatedbody; a tool assembly including a blade coupled to a distal end of thewaveguide, the blade defining a blade lumen, the blade lumen havingclosed proximal and distal ends, the blade defining an output incommunication with the blade lumen towards the proximal end of the bladelumen; an inflow conduit entering the blade lumen via the output andextending distally through the blade lumen, the inflow conduit definingan open distal end positioned within the blade lumen adjacent the distalend of the blade lumen; and a return conduit defining an open distal endpositioned within the blade lumen adjacent the proximal end of the bladelumen, the return conduit exiting the blade lumen via the output andextending proximally therefrom.